//Filament Group modification note:  
//This version of excanvas is modified to support lazy loading of this file. More info here: http://pipwerks.com/2009/03/12/lazy-loading-excanvasjs/  
  
// Copyright 2006 Google Inc.  
//  
// Licensed under the Apache License, Version 2.0 (the "License");  
// you may not use this file except in compliance with the License.  
// You may obtain a copy of the License at  
//  
//   http://www.apache.org/licenses/LICENSE-2.0  
//  
// Unless required by applicable law or agreed to in writing, software  
// distributed under the License is distributed on an "AS IS" BASIS,  
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  
// See the License for the specific language governing permissions and  
// limitations under the License.  
  
  
// Known Issues:  
//  
// * Patterns are not implemented.  
// * Radial gradient are not implemented. The VML version of these look very  
//   different from the canvas one.  
// * Clipping paths are not implemented.  
// * Coordsize. The width and height attribute have higher priority than the  
//   width and height style values which isn't correct.  
// * Painting mode isn't implemented.  
// * Canvas width/height should is using content-box by default. IE in  
//   Quirks mode will draw the canvas using border-box. Either change your  
//   doctype to HTML5  
//   (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype)  
//   or use Box Sizing Behavior from WebFX  
//   (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html)  
// * Non uniform scaling does not correctly scale strokes.  
// * Optimize. There is always room for speed improvements.  
  
// Only add this code if we do not already have a canvas implementation  
if (!document.createElement('canvas').getContext) {  
  
(function() {  
  
  // alias some functions to make (compiled) code shorter  
  var m = Math;  
  var mr = m.round;  
  var ms = m.sin;  
  var mc = m.cos;  
  var abs = m.abs;  
  var sqrt = m.sqrt;  
  
  // this is used for sub pixel precision  
  var Z = 10;  
  var Z2 = Z / 2;  
  
  /** 
   * This funtion is assigned to the <canvas> elements as element.getContext(). 
   * @this {HTMLElement} 
   * @return {CanvasRenderingContext2D_} 
   */  
  function getContext() {  
    return this.context_ ||  
        (this.context_ = new CanvasRenderingContext2D_(this));  
  }  
  
  var slice = Array.prototype.slice;  
  
  /** 
   * Binds a function to an object. The returned function will always use the 
   * passed in {@code obj} as {@code this}. 
   * 
   * Example: 
   * 
   *   g = bind(f, obj, a, b) 
   *   g(c, d) // will do f.call(obj, a, b, c, d) 
   * 
   * @param {Function} f The function to bind the object to 
   * @param {Object} obj The object that should act as this when the function 
   *     is called 
   * @param {*} var_args Rest arguments that will be used as the initial 
   *     arguments when the function is called 
   * @return {Function} A new function that has bound this 
   */  
  function bind(f, obj, var_args) {  
    var a = slice.call(arguments, 2);  
    return function() {  
      return f.apply(obj, a.concat(slice.call(arguments)));  
    };  
  }  
  
  var G_vmlCanvasManager_ = {  
    init: function(opt_doc) {  
    if (/MSIE/.test(navigator.userAgent) && !window.opera) {  
        var doc = opt_doc || document;  
        // Create a dummy element so that IE will allow canvas elements to be  
        // recognized.  
        doc.createElement('canvas');  
   
        if(doc.readyState !== "complete"){  
   
            doc.attachEvent('onreadystatechange', bind(this.init_, this, doc));  
   
        } else {  
   
           this.init_(doc);  
   
        }  
   
    }  
},  
  
    init_: function(doc) {  
      // create xmlns  
      if (!doc.namespaces['g_vml_']) {  
        doc.namespaces.add('g_vml_', 'urn:schemas-microsoft-com:vml',  
                           '#default#VML');  
  
      }  
      if (!doc.namespaces['g_o_']) {  
        doc.namespaces.add('g_o_', 'urn:schemas-microsoft-com:office:office',  
                           '#default#VML');  
      }  
  
      // Setup default CSS.  Only add one style sheet per document  
      if (!doc.styleSheets['ex_canvas_']) {  
        var ss = doc.createStyleSheet();  
        ss.owningElement.id = 'ex_canvas_';  
        ss.cssText = 'canvas{display:inline-block;overflow:hidden;' +  
            // default size is 300x150 in Gecko and Opera  
            'text-align:left;width:300px;height:150px}' +  
            'g_vml_\\:*{behavior:url(#default#VML)}' +  
            'g_o_\\:*{behavior:url(#default#VML)}';  
  
      }  
  
      // find all canvas elements  
      var els = doc.getElementsByTagName('canvas');  
      for (var i = 0; i < els.length; i++) {  
        this.initElement(els[i]);  
      }  
    },  
  
    /** 
     * Public initializes a canvas element so that it can be used as canvas 
     * element from now on. This is called automatically before the page is 
     * loaded but if you are creating elements using createElement you need to 
     * make sure this is called on the element. 
     * @param {HTMLElement} el The canvas element to initialize. 
     * @return {HTMLElement} the element that was created. 
     */  
    initElement: function(el) {  
      if (!el.getContext) {  
  
        el.getContext = getContext;  
  
        // Remove fallback content. There is no way to hide text nodes so we  
        // just remove all childNodes. We could hide all elements and remove  
        // text nodes but who really cares about the fallback content.  
        el.innerHTML = '';  
  
        // do not use inline function because that will leak memory  
        el.attachEvent('onpropertychange', onPropertyChange);  
        el.attachEvent('onresize', onResize);  
  
        var attrs = el.attributes;  
        if (attrs.width && attrs.width.specified) {  
          // TODO: use runtimeStyle and coordsize  
          // el.getContext().setWidth_(attrs.width.nodeValue);  
          el.style.width = attrs.width.nodeValue + 'px';  
        } else {  
          el.width = el.clientWidth;  
        }  
        if (attrs.height && attrs.height.specified) {  
          // TODO: use runtimeStyle and coordsize  
          // el.getContext().setHeight_(attrs.height.nodeValue);  
          el.style.height = attrs.height.nodeValue + 'px';  
        } else {  
          el.height = el.clientHeight;  
        }  
        //el.getContext().setCoordsize_()  
      }  
      return el;  
    }  
  };  
  
  function onPropertyChange(e) {  
    var el = e.srcElement;  
  
    switch (e.propertyName) {  
      case 'width':  
        el.style.width = el.attributes.width.nodeValue + 'px';  
        el.getContext().clearRect();  
        break;  
      case 'height':  
        el.style.height = el.attributes.height.nodeValue + 'px';  
        el.getContext().clearRect();  
        break;  
    }  
  }  
  
  function onResize(e) {  
    var el = e.srcElement;  
    if (el.firstChild) {  
      el.firstChild.style.width =  el.clientWidth + 'px';  
      el.firstChild.style.height = el.clientHeight + 'px';  
    }  
  }  
  
  G_vmlCanvasManager_.init();  
  
  // precompute "00" to "FF"  
  var dec2hex = [];  
  for (var i = 0; i < 16; i++) {  
    for (var j = 0; j < 16; j++) {  
      dec2hex[i * 16 + j] = i.toString(16) + j.toString(16);  
    }  
  }  
  
  function createMatrixIdentity() {  
    return [  
      [1, 0, 0],  
      [0, 1, 0],  
      [0, 0, 1]  
    ];  
  }  
  
  function matrixMultiply(m1, m2) {  
    var result = createMatrixIdentity();  
  
    for (var x = 0; x < 3; x++) {  
      for (var y = 0; y < 3; y++) {  
        var sum = 0;  
  
        for (var z = 0; z < 3; z++) {  
          sum += m1[x][z] * m2[z][y];  
        }  
  
        result[x][y] = sum;  
      }  
    }  
    return result;  
  }  
  
  function copyState(o1, o2) {  
    o2.fillStyle     = o1.fillStyle;  
    o2.lineCap       = o1.lineCap;  
    o2.lineJoin      = o1.lineJoin;  
    o2.lineWidth     = o1.lineWidth;  
    o2.miterLimit    = o1.miterLimit;  
    o2.shadowBlur    = o1.shadowBlur;  
    o2.shadowColor   = o1.shadowColor;  
    o2.shadowOffsetX = o1.shadowOffsetX;  
    o2.shadowOffsetY = o1.shadowOffsetY;  
    o2.strokeStyle   = o1.strokeStyle;  
    o2.globalAlpha   = o1.globalAlpha;  
    o2.arcScaleX_    = o1.arcScaleX_;  
    o2.arcScaleY_    = o1.arcScaleY_;  
    o2.lineScale_    = o1.lineScale_;  
  }  
  
  function processStyle(styleString) {  
    var str, alpha = 1;  
  
    styleString = String(styleString);  
    if (styleString.substring(0, 3) == 'rgb') {  
      var start = styleString.indexOf('(', 3);  
      var end = styleString.indexOf(')', start + 1);  
      var guts = styleString.substring(start + 1, end).split(',');  
  
      str = '#';  
      for (var i = 0; i < 3; i++) {  
        str += dec2hex[Number(guts[i])];  
      }  
  
      if (guts.length == 4 && styleString.substr(3, 1) == 'a') {  
        alpha = guts[3];  
      }  
    } else {  
      str = styleString;  
    }  
  
    return {color: str, alpha: alpha};  
  }  
  
  function processLineCap(lineCap) {  
    switch (lineCap) {  
      case 'butt':  
        return 'flat';  
      case 'round':  
        return 'round';  
      case 'square':  
      default:  
        return 'square';  
    }  
  }  
  
  /** 
   * This class implements CanvasRenderingContext2D interface as described by 
   * the WHATWG. 
   * @param {HTMLElement} surfaceElement The element that the 2D context should 
   * be associated with 
   */  
  function CanvasRenderingContext2D_(surfaceElement) {  
    this.m_ = createMatrixIdentity();  
  
    this.mStack_ = [];  
    this.aStack_ = [];  
    this.currentPath_ = [];  
  
    // Canvas context properties  
    this.strokeStyle = '#000';  
    this.fillStyle = '#000';  
  
    this.lineWidth = 1;  
    this.lineJoin = 'miter';  
    this.lineCap = 'butt';  
    this.miterLimit = Z * 1;  
    this.globalAlpha = 1;  
    this.canvas = surfaceElement;  
  
    var el = surfaceElement.ownerDocument.createElement('div');  
    el.style.width =  surfaceElement.clientWidth + 'px';  
    el.style.height = surfaceElement.clientHeight + 'px';  
    el.style.overflow = 'hidden';  
    el.style.position = 'absolute';  
    surfaceElement.appendChild(el);  
  
    this.element_ = el;  
    this.arcScaleX_ = 1;  
    this.arcScaleY_ = 1;  
    this.lineScale_ = 1;  
  }  
  
  var contextPrototype = CanvasRenderingContext2D_.prototype;  
  contextPrototype.clearRect = function() {  
    this.element_.innerHTML = '';  
  };  
  
  contextPrototype.beginPath = function() {  
    // TODO: Branch current matrix so that save/restore has no effect  
    //       as per safari docs.  
    this.currentPath_ = [];  
  };  
  
  contextPrototype.moveTo = function(aX, aY) {  
    var p = this.getCoords_(aX, aY);  
    this.currentPath_.push({type: 'moveTo', x: p.x, y: p.y});  
    this.currentX_ = p.x;  
    this.currentY_ = p.y;  
  };  
  
  contextPrototype.lineTo = function(aX, aY) {  
    var p = this.getCoords_(aX, aY);  
    this.currentPath_.push({type: 'lineTo', x: p.x, y: p.y});  
  
    this.currentX_ = p.x;  
    this.currentY_ = p.y;  
  };  
  
  contextPrototype.bezierCurveTo = function(aCP1x, aCP1y,  
                                            aCP2x, aCP2y,  
                                            aX, aY) {  
    var p = this.getCoords_(aX, aY);  
    var cp1 = this.getCoords_(aCP1x, aCP1y);  
    var cp2 = this.getCoords_(aCP2x, aCP2y);  
    bezierCurveTo(this, cp1, cp2, p);  
  };  
  
  // Helper function that takes the already fixed cordinates.  
  function bezierCurveTo(self, cp1, cp2, p) {  
    self.currentPath_.push({  
      type: 'bezierCurveTo',  
      cp1x: cp1.x,  
      cp1y: cp1.y,  
      cp2x: cp2.x,  
      cp2y: cp2.y,  
      x: p.x,  
      y: p.y  
    });  
    self.currentX_ = p.x;  
    self.currentY_ = p.y;  
  }  
  
  contextPrototype.quadraticCurveTo = function(aCPx, aCPy, aX, aY) {  
    // the following is lifted almost directly from  
    // http://developer.mozilla.org/en/docs/Canvas_tutorial:Drawing_shapes  
  
    var cp = this.getCoords_(aCPx, aCPy);  
    var p = this.getCoords_(aX, aY);  
  
    var cp1 = {  
      x: this.currentX_ + 2.0 / 3.0 * (cp.x - this.currentX_),  
      y: this.currentY_ + 2.0 / 3.0 * (cp.y - this.currentY_)  
    };  
    var cp2 = {  
      x: cp1.x + (p.x - this.currentX_) / 3.0,  
      y: cp1.y + (p.y - this.currentY_) / 3.0  
    };  
  
    bezierCurveTo(this, cp1, cp2, p);  
  };  
  
  contextPrototype.arc = function(aX, aY, aRadius,  
                                  aStartAngle, aEndAngle, aClockwise) {  
    aRadius *= Z;  
    var arcType = aClockwise ? 'at' : 'wa';  
  
    var xStart = aX + mc(aStartAngle) * aRadius - Z2;  
    var yStart = aY + ms(aStartAngle) * aRadius - Z2;  
  
    var xEnd = aX + mc(aEndAngle) * aRadius - Z2;  
    var yEnd = aY + ms(aEndAngle) * aRadius - Z2;  
  
    // IE won't render arches drawn counter clockwise if xStart == xEnd.  
    if (xStart == xEnd && !aClockwise) {  
      xStart += 0.125; // Offset xStart by 1/80 of a pixel. Use something  
                       // that can be represented in binary  
    }  
  
    var p = this.getCoords_(aX, aY);  
    var pStart = this.getCoords_(xStart, yStart);  
    var pEnd = this.getCoords_(xEnd, yEnd);  
  
    this.currentPath_.push({type: arcType,  
                           x: p.x,  
                           y: p.y,  
                           radius: aRadius,  
                           xStart: pStart.x,  
                           yStart: pStart.y,  
                           xEnd: pEnd.x,  
                           yEnd: pEnd.y});  
  
  };  
  
  contextPrototype.rect = function(aX, aY, aWidth, aHeight) {  
    this.moveTo(aX, aY);  
    this.lineTo(aX + aWidth, aY);  
    this.lineTo(aX + aWidth, aY + aHeight);  
    this.lineTo(aX, aY + aHeight);  
    this.closePath();  
  };  
  
  contextPrototype.strokeRect = function(aX, aY, aWidth, aHeight) {  
    var oldPath = this.currentPath_;  
    this.beginPath();  
  
    this.moveTo(aX, aY);  
    this.lineTo(aX + aWidth, aY);  
    this.lineTo(aX + aWidth, aY + aHeight);  
    this.lineTo(aX, aY + aHeight);  
    this.closePath();  
    this.stroke();  
  
    this.currentPath_ = oldPath;  
  };  
  
  contextPrototype.fillRect = function(aX, aY, aWidth, aHeight) {  
    var oldPath = this.currentPath_;  
    this.beginPath();  
  
    this.moveTo(aX, aY);  
    this.lineTo(aX + aWidth, aY);  
    this.lineTo(aX + aWidth, aY + aHeight);  
    this.lineTo(aX, aY + aHeight);  
    this.closePath();  
    this.fill();  
  
    this.currentPath_ = oldPath;  
  };  
  
  contextPrototype.createLinearGradient = function(aX0, aY0, aX1, aY1) {  
    var gradient = new CanvasGradient_('gradient');  
    gradient.x0_ = aX0;  
    gradient.y0_ = aY0;  
    gradient.x1_ = aX1;  
    gradient.y1_ = aY1;  
    return gradient;  
  };  
  
  contextPrototype.createRadialGradient = function(aX0, aY0, aR0,  
                                                   aX1, aY1, aR1) {  
    var gradient = new CanvasGradient_('gradientradial');  
    gradient.x0_ = aX0;  
    gradient.y0_ = aY0;  
    gradient.r0_ = aR0;  
    gradient.x1_ = aX1;  
    gradient.y1_ = aY1;  
    gradient.r1_ = aR1;  
    return gradient;  
  };  
  
  contextPrototype.drawImage = function(image, var_args) {  
    var dx, dy, dw, dh, sx, sy, sw, sh;  
  
    // to find the original width we overide the width and height  
    var oldRuntimeWidth = image.runtimeStyle.width;  
    var oldRuntimeHeight = image.runtimeStyle.height;  
    image.runtimeStyle.width = 'auto';  
    image.runtimeStyle.height = 'auto';  
  
    // get the original size  
    var w = image.width;  
    var h = image.height;  
  
    // and remove overides  
    image.runtimeStyle.width = oldRuntimeWidth;  
    image.runtimeStyle.height = oldRuntimeHeight;  
  
    if (arguments.length == 3) {  
      dx = arguments[1];  
      dy = arguments[2];  
      sx = sy = 0;  
      sw = dw = w;  
      sh = dh = h;  
    } else if (arguments.length == 5) {  
      dx = arguments[1];  
      dy = arguments[2];  
      dw = arguments[3];  
      dh = arguments[4];  
      sx = sy = 0;  
      sw = w;  
      sh = h;  
    } else if (arguments.length == 9) {  
      sx = arguments[1];  
      sy = arguments[2];  
      sw = arguments[3];  
      sh = arguments[4];  
      dx = arguments[5];  
      dy = arguments[6];  
      dw = arguments[7];  
      dh = arguments[8];  
    } else {  
      throw Error('Invalid number of arguments');  
    }  
  
    var d = this.getCoords_(dx, dy);  
  
    var w2 = sw / 2;  
    var h2 = sh / 2;  
  
    var vmlStr = [];  
  
    var W = 10;  
    var H = 10;  
  
    // For some reason that I've now forgotten, using divs didn't work  
    vmlStr.push(' <g_vml_:group',  
                ' coordsize="', Z * W, ',', Z * H, '"',  
                ' coordorigin="0,0"' ,  
                ' style="width:', W, 'px;height:', H, 'px;position:absolute;');  
  
    // If filters are necessary (rotation exists), create them  
    // filters are bog-slow, so only create them if abbsolutely necessary  
    // The following check doesn't account for skews (which don't exist  
    // in the canvas spec (yet) anyway.  
  
    if (this.m_[0][0] != 1 || this.m_[0][1]) {  
      var filter = [];  
  
      // Note the 12/21 reversal  
      filter.push('M11=', this.m_[0][0], ',',  
                  'M12=', this.m_[1][0], ',',  
                  'M21=', this.m_[0][1], ',',  
                  'M22=', this.m_[1][1], ',',  
                  'Dx=', mr(d.x / Z), ',',  
                  'Dy=', mr(d.y / Z), '');  
  
      // Bounding box calculation (need to minimize displayed area so that  
      // filters don't waste time on unused pixels.  
      var max = d;  
      var c2 = this.getCoords_(dx + dw, dy);  
      var c3 = this.getCoords_(dx, dy + dh);  
      var c4 = this.getCoords_(dx + dw, dy + dh);  
  
      max.x = m.max(max.x, c2.x, c3.x, c4.x);  
      max.y = m.max(max.y, c2.y, c3.y, c4.y);  
  
      vmlStr.push('padding:0 ', mr(max.x / Z), 'px ', mr(max.y / Z),  
                  'px 0;filter:progid:DXImageTransform.Microsoft.Matrix(',  
                  filter.join(''), ", sizingmethod='clip');")  
    } else {  
      vmlStr.push('top:', mr(d.y / Z), 'px;left:', mr(d.x / Z), 'px;');  
    }  
  
    vmlStr.push(' ">' ,  
                '<g_vml_:image src="', image.src, '"',  
                ' style="width:', Z * dw, 'px;',  
                ' height:', Z * dh, 'px;"',  
                ' cropleft="', sx / w, '"',  
                ' croptop="', sy / h, '"',  
                ' cropright="', (w - sx - sw) / w, '"',  
                ' cropbottom="', (h - sy - sh) / h, '"',  
                ' />',  
                '</g_vml_:group>');  
  
    this.element_.insertAdjacentHTML('BeforeEnd',  
                                    vmlStr.join(''));  
  };  
  
  contextPrototype.stroke = function(aFill) {  
    var lineStr = [];  
    var lineOpen = false;  
    var a = processStyle(aFill ? this.fillStyle : this.strokeStyle);  
    var color = a.color;  
    var opacity = a.alpha * this.globalAlpha;  
  
    var W = 10;  
    var H = 10;  
  
    lineStr.push('<g_vml_:shape',  
                 ' filled="', !!aFill, '"',  
                 ' style="position:absolute;width:', W, 'px;height:', H, 'px;"',  
                 ' coordorigin="0 0" coordsize="', Z * W, ' ', Z * H, '"',  
                 ' stroked="', !aFill, '"',  
                 ' path="');  
  
    var newSeq = false;  
    var min = {x: null, y: null};  
    var max = {x: null, y: null};  
  
    for (var i = 0; i < this.currentPath_.length; i++) {  
      var p = this.currentPath_[i];  
      var c;  
  
      switch (p.type) {  
        case 'moveTo':  
          c = p;  
          lineStr.push(' m ', mr(p.x), ',', mr(p.y));  
          break;  
        case 'lineTo':  
          lineStr.push(' l ', mr(p.x), ',', mr(p.y));  
          break;  
        case 'close':  
          lineStr.push(' x ');  
          p = null;  
          break;  
        case 'bezierCurveTo':  
          lineStr.push(' c ',  
                       mr(p.cp1x), ',', mr(p.cp1y), ',',  
                       mr(p.cp2x), ',', mr(p.cp2y), ',',  
                       mr(p.x), ',', mr(p.y));  
          break;  
        case 'at':  
        case 'wa':  
          lineStr.push(' ', p.type, ' ',  
                       mr(p.x - this.arcScaleX_ * p.radius), ',',  
                       mr(p.y - this.arcScaleY_ * p.radius), ' ',  
                       mr(p.x + this.arcScaleX_ * p.radius), ',',  
                       mr(p.y + this.arcScaleY_ * p.radius), ' ',  
                       mr(p.xStart), ',', mr(p.yStart), ' ',  
                       mr(p.xEnd), ',', mr(p.yEnd));  
          break;  
      }  
  
  
      // TODO: Following is broken for curves due to  
      //       move to proper paths.  
  
      // Figure out dimensions so we can do gradient fills  
      // properly  
      if (p) {  
        if (min.x == null || p.x < min.x) {  
          min.x = p.x;  
        }  
        if (max.x == null || p.x > max.x) {  
          max.x = p.x;  
        }  
        if (min.y == null || p.y < min.y) {  
          min.y = p.y;  
        }  
        if (max.y == null || p.y > max.y) {  
          max.y = p.y;  
        }  
      }  
    }  
    lineStr.push(' ">');  
  
    if (!aFill) {  
      var lineWidth = this.lineScale_ * this.lineWidth;  
  
      // VML cannot correctly render a line if the width is less than 1px.  
      // In that case, we dilute the color to make the line look thinner.  
      if (lineWidth < 1) {  
        opacity *= lineWidth;  
      }  
  
      lineStr.push(  
        '<g_vml_:stroke',  
        ' opacity="', opacity, '"',  
        ' joinstyle="', this.lineJoin, '"',  
        ' miterlimit="', this.miterLimit, '"',  
        ' endcap="', processLineCap(this.lineCap), '"',  
        ' weight="', lineWidth, 'px"',  
        ' color="', color, '" />'  
      );  
    } else if (typeof this.fillStyle == 'object') {  
      var fillStyle = this.fillStyle;  
      var angle = 0;  
      var focus = {x: 0, y: 0};  
  
      // additional offset  
      var shift = 0;  
      // scale factor for offset  
      var expansion = 1;  
  
      if (fillStyle.type_ == 'gradient') {  
        var x0 = fillStyle.x0_ / this.arcScaleX_;  
        var y0 = fillStyle.y0_ / this.arcScaleY_;  
        var x1 = fillStyle.x1_ / this.arcScaleX_;  
        var y1 = fillStyle.y1_ / this.arcScaleY_;  
        var p0 = this.getCoords_(x0, y0);  
        var p1 = this.getCoords_(x1, y1);  
        var dx = p1.x - p0.x;  
        var dy = p1.y - p0.y;  
        angle = Math.atan2(dx, dy) * 180 / Math.PI;  
  
        // The angle should be a non-negative number.  
        if (angle < 0) {  
          angle += 360;  
        }  
  
        // Very small angles produce an unexpected result because they are  
        // converted to a scientific notation string.  
        if (angle < 1e-6) {  
          angle = 0;  
        }  
      } else {  
        var p0 = this.getCoords_(fillStyle.x0_, fillStyle.y0_);  
        var width  = max.x - min.x;  
        var height = max.y - min.y;  
        focus = {  
          x: (p0.x - min.x) / width,  
          y: (p0.y - min.y) / height  
        };  
  
        width  /= this.arcScaleX_ * Z;  
        height /= this.arcScaleY_ * Z;  
        var dimension = m.max(width, height);  
        shift = 2 * fillStyle.r0_ / dimension;  
        expansion = 2 * fillStyle.r1_ / dimension - shift;  
      }  
  
      // We need to sort the color stops in ascending order by offset,  
      // otherwise IE won't interpret it correctly.  
      var stops = fillStyle.colors_;  
      stops.sort(function(cs1, cs2) {  
        return cs1.offset - cs2.offset;  
      });  
  
      var length = stops.length;  
      var color1 = stops[0].color;  
      var color2 = stops[length - 1].color;  
      var opacity1 = stops[0].alpha * this.globalAlpha;  
      var opacity2 = stops[length - 1].alpha * this.globalAlpha;  
  
      var colors = [];  
      for (var i = 0; i < length; i++) {  
        var stop = stops[i];  
        colors.push(stop.offset * expansion + shift + ' ' + stop.color);  
      }  
  
      // When colors attribute is used, the meanings of opacity and o:opacity2  
      // are reversed.  
      lineStr.push('<g_vml_:fill type="', fillStyle.type_, '"',  
                   ' method="none" focus="100%"',  
                   ' color="', color1, '"',  
                   ' color2="', color2, '"',  
                   ' colors="', colors.join(','), '"',  
                   ' opacity="', opacity2, '"',  
                   ' g_o_:opacity2="', opacity1, '"',  
                   ' angle="', angle, '"',  
                   ' focusposition="', focus.x, ',', focus.y, '" />');  
    } else {  
      lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity,  
                   '" />');  
    }  
  
    lineStr.push('</g_vml_:shape>');  
  
    this.element_.insertAdjacentHTML('beforeEnd', lineStr.join(''));  
  };  
  
  contextPrototype.fill = function() {  
    this.stroke(true);  
  }  
  
  contextPrototype.closePath = function() {  
    this.currentPath_.push({type: 'close'});  
  };  
  
  /** 
   * @private 
   */  
  contextPrototype.getCoords_ = function(aX, aY) {  
    var m = this.m_;  
    return {  
      x: Z * (aX * m[0][0] + aY * m[1][0] + m[2][0]) - Z2,  
      y: Z * (aX * m[0][1] + aY * m[1][1] + m[2][1]) - Z2  
    }  
  };  
  
  contextPrototype.save = function() {  
    var o = {};  
    copyState(this, o);  
    this.aStack_.push(o);  
    this.mStack_.push(this.m_);  
    this.m_ = matrixMultiply(createMatrixIdentity(), this.m_);  
  };  
  
  contextPrototype.restore = function() {  
    copyState(this.aStack_.pop(), this);  
    this.m_ = this.mStack_.pop();  
  };  
  
  function matrixIsFinite(m) {  
    for (var j = 0; j < 3; j++) {  
      for (var k = 0; k < 2; k++) {  
        if (!isFinite(m[j][k]) || isNaN(m[j][k])) {  
          return false;  
        }  
      }  
    }  
    return true;  
  }  
  
  function setM(ctx, m, updateLineScale) {  
    if (!matrixIsFinite(m)) {  
      return;  
    }  
    ctx.m_ = m;  
  
    if (updateLineScale) {  
      // Get the line scale.  
      // Determinant of this.m_ means how much the area is enlarged by the  
      // transformation. So its square root can be used as a scale factor  
      // for width.  
      var det = m[0][0] * m[1][1] - m[0][1] * m[1][0];  
      ctx.lineScale_ = sqrt(abs(det));  
    }  
  }  
  
  contextPrototype.translate = function(aX, aY) {  
    var m1 = [  
      [1,  0,  0],  
      [0,  1,  0],  
      [aX, aY, 1]  
    ];  
  
    setM(this, matrixMultiply(m1, this.m_), false);  
  };  
  
  contextPrototype.rotate = function(aRot) {  
    var c = mc(aRot);  
    var s = ms(aRot);  
  
    var m1 = [  
      [c,  s, 0],  
      [-s, c, 0],  
      [0,  0, 1]  
    ];  
  
    setM(this, matrixMultiply(m1, this.m_), false);  
  };  
  
  contextPrototype.scale = function(aX, aY) {  
    this.arcScaleX_ *= aX;  
    this.arcScaleY_ *= aY;  
    var m1 = [  
      [aX, 0,  0],  
      [0,  aY, 0],  
      [0,  0,  1]  
    ];  
  
    setM(this, matrixMultiply(m1, this.m_), true);  
  };  
  
  contextPrototype.transform = function(m11, m12, m21, m22, dx, dy) {  
    var m1 = [  
      [m11, m12, 0],  
      [m21, m22, 0],  
      [dx,  dy,  1]  
    ];  
  
    setM(this, matrixMultiply(m1, this.m_), true);  
  };  
  
  contextPrototype.setTransform = function(m11, m12, m21, m22, dx, dy) {  
    var m = [  
      [m11, m12, 0],  
      [m21, m22, 0],  
      [dx,  dy,  1]  
    ];  
  
    setM(this, m, true);  
  };  
  
  /******** STUBS ********/  
  contextPrototype.clip = function() {  
    // TODO: Implement  
  };  
  
  contextPrototype.arcTo = function() {  
    // TODO: Implement  
  };  
  
  contextPrototype.createPattern = function() {  
    return new CanvasPattern_;  
  };  
  
  // Gradient / Pattern Stubs  
  function CanvasGradient_(aType) {  
    this.type_ = aType;  
    this.x0_ = 0;  
    this.y0_ = 0;  
    this.r0_ = 0;  
    this.x1_ = 0;  
    this.y1_ = 0;  
    this.r1_ = 0;  
    this.colors_ = [];  
  }  
  
  CanvasGradient_.prototype.addColorStop = function(aOffset, aColor) {  
    aColor = processStyle(aColor);  
    this.colors_.push({offset: aOffset,  
                       color: aColor.color,  
                       alpha: aColor.alpha});  
  };  
  
  function CanvasPattern_() {}  
  
  // set up externs  
  G_vmlCanvasManager = G_vmlCanvasManager_;  
  CanvasRenderingContext2D = CanvasRenderingContext2D_;  
  CanvasGradient = CanvasGradient_;  
  CanvasPattern = CanvasPattern_;  
  
})();  
  
} // if  